The present disclosure generally relates to an implant such as a bone plate for use in orthopedic surgery, preferably for fixation of bone. The disclosure further relates to an implant system and a method for fracture fixation of bone.
Bone plates may be employed for treating periarticular and/or intra-articular fractures of, for example, the proximal humerus, distal femur, proximal tibia or the distal tibia. Such bone plates are available in a plurality of variations for different applications and can have an I-, T-, L-, cloverleaf- or calcaneal-shape.
Bone plates for periarticular and other fractures can include threaded and unthreaded holes to receive locking and non-locking screws, respectively. The locking screws can be secured to the bone plate, wherein a threaded head of the locking screw mates with a corresponding thread on an inner surface of a plate hole. Further, the non-locking screws (such as compression or cortical screws) are typically inserted through plate holes having an unthreaded curved or conical portion into bone for providing compression of a fracture by pushing bone fragments towards each other. The configuration of the plate holes is often crucial for the medical success of the implant.
U.S. Pat. No. 5,601,553 relates to an anterior thoracolumbar locking bone plate. The bone plate comprises a plurality of threaded screw holes which are located at both extreme ends of the plate for receiving locking screws. Further, the bone plate is provided with elongated holes with a camming surface for receiving temporary screws. A threaded central hole is arranged at a midpoint of the entire bone plate. The bone plate further comprises a curved lower surface for contacting to bone, and an upper surface having two intersecting planes which meet at a central ridge portion.
U.S. Pat. No. 7,776,076 relates to bone plates having an I-, L- or T-shape. The head portion of the bone plate includes threaded screw holes which are orientated such that the axes of the holes intersect at a point beneath the lower surface of the bone plate. Further, bone screws are threadedly engaged with the holes for rigidly anchoring the bone plate to the fractured bone.
U.S. Pat. No. 7,137,987 relates to a bone plating system for fixating distal or proximal ends of long bones. The bone plate has a T- or fork-shaped head portion. The head portion of the bone plate includes a plurality of threaded plate holes for receiving locking bone screws. Further, one or more non-threaded plate holes for receiving a non-locking cancellous bone screw are provided near the peripheral side of the head portion.
The conventional bone plate systems for fracture fixation of bone have several drawbacks. In the vicinity of a compression screw, conventional bone plates cannot guarantee a desired screw-plate-bone construct stability, since compression screws cannot be locked to unthreaded plate holes. Therefore, it is possible that the bone plate is shifted in an undesired direction or is pulled out. Further, the bone plate may lose the contact between the bone contacting surface of the plate and the bone. Thus, the medical success may decrease and rapid healing may not achieved.